Page 1
1-4. CP1 STROBO CIRCUIT DESCRIPTION
1. Charging Circuit
When UNREG power is supplied to the charge circuit and the
CHG signal becomes High (3.3 V), the charging circuit starts
operating and the main electorolytic capacitor is charged with
high-voltage direct current.
However, when the CHG signal is Low (0 V), the charging
circuit does not operate.
1-1. Power switch
When the CHG signal switches to Hi, Q5406 turns ON and
the charging circuit starts operating.
1-2. Power supply filter
L5401 and C5405 constitute the power supply filter. They
smooth out ripples in the current which accompany the switching of the oscillation transformer.
1-3. Oscillation circuit
This circuit generates an AC voltage (pulse) in order to increase the UNREG power supply voltage when drops in current occur. This circuit generates a drive pulse with a frequency
of approximately 50-100 kHz. Because self-excited light omission is used, the oscillation frequency changes according to
the drive conditions.
2. Light Emission Circuit
When RDY and TRIG signals are input from the ASIC, the
stroboscope emits light.
2-1. Emission control circuit
When the RDY signal is input to the emission control circuit,
Q5409 switches on and preparation is made to let current
flow to the light emitting element. Moreover, when a STOP
signal is input, the stroboscope stops emitting light.
2-2. Trigger circuit
When a TRIG signal is input to the trigger circuit, D5405
switches on, a high-voltage pulse of several kilovolts is generated inside the trigger circuit, and this pulse is then applied
to the light emitting part.
2-3. Light emitting element
When the high-voltage pulse form the trigger circuit is applied to the light emitting part, currnet flows to the light emitting element and light is emitted.
Beware of electric shocks.
1-4. Oscillation transformer
The low-voltage alternating current which is generated by the
oscillation control circuit is converted to a high-voltage alternating current by the oscillation transformer.
1-5. Rectifier circuit
The high-voltage alternating current which is generated at
the secondary side of T5401 is rectified to produce a highvoltage direct current and is accumulated at electrolytic capacitor C5412 on the main circuit board.
1-6. Voltage monitoring circuit
This circuit is used to maintain the voltage accumulated at
C5412 at a constance level.
After the charging voltage is divided and converted to a lower
voltage by R5417 and R5419, it is output to the SY-A block as
the monitoring voltage VMONIT. When this VMONIT voltage
reaches a specified level at the SY-A block, the CHG signal is
switched to Low and charging is interrupted.
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Page 2
1-5. SY-A CIRCUIT DESCRIPTION
1. Configuration and Functions
For the overall configuration of the SY-A block, refer to the block diagram. The SY-A block centers around a 8-bit microprocessor
(IC301), and controls camera system condition (mode).
The 8-bit microprocessor handles the following functions.
1. Operation key input, 2. Clock control, 3. Power ON/OFF, 4. Strobe charge control.
Pin
1~2
3
4
5
6
7
8
9
10~12
13
14
15~16
17~18
19
20~23
24
25~26
27
28
29
30 SDIR
31 BAT_OFF
32 +3.2_SW
33
34 P ON
35~36
37
38
39~40
41
42
43
44~45
46
47
48~52
53
54~74
75~78
79~80
Signal
NOT USED
AVSS
AVR
AVCC
VDD3
UNREG (S)
VDD3
STROBO_V
P54~P56
VSS
DC_IN
X1, X0
MOD1, 0
P. ST.
S10~S13
P04
P05~P06
PLL_EN
USB_CNT
REQACK
RESET B
NOT USED
VF_LED_G
EXT_IRQ1
SDATA
SCLK
SELF_LED_R
NOT USED
X0A, X1A
BUZZER
CHARGE
NOT USED
VCC
NOT USED
SO0~SO3
NOT USED
I/O
O
O
O
O
O
O
O
I/O
O
O
O
O
O
Outline
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I
I
I
I
I
-
I
-
I
I
I
I
I
I
I
I
-
-
-
-
-
-
-
-
GND
Analog power
Analog power
Main (ASIC system) power detection
Battery power input (analog input)
Main (ASIC system) power detection
Strobo charge voltage input (analog input)
Connect to GND through register
GND
AC adaptor connection detection (analog input)
Main clock oscillation terminal (4 MHz)
Connect to GND
Reset input
Key matrix input
Connect to GND through register
Connect to GND through register
ASIC PLL permission signal
USB connection detection H : Connection
Serial communication control signal
Serial communication control signal
Battery OFF detection H : OFF
3.2 V power (switch)
Reset output to ASIC L : Reset
DC/DC converter (analog) ON/OFF signal H : ON
-
VF LED (green) ON/OFF signal L : Light
External interruption signal
Serial communication control signal
Serial communication control signal
Self LED (red) ON/OFF signal L : Light
-
Sub clock oscillation terminal (32.768 kHz)
Buzzer output terminal
Strobo charge ON/OFF signal L : ON
-
Digital power
-
Key matrix output
-
Table 4-1. 8-bit Microprocessor Port Specification
– 8 –
Page 3
2. Internal Communication Bus
The SY-A block carries out overall control of camera operation by detecting the input from the keyboard and the condition of the
camera circuits. The 8-bit microprocessor reads the signals from each sensor element as input data and outputs this data to the
camera circuits (ASIC) or to the LCD display device as operation mode setting data. Fig. 4-1 shows the internal communication
between the 8-bit microprocessor, ASIC and SPARC lite circuits.
RESET B
REQACK
8-bit
Microprocessor
Fig. 4-1 Internal Bus Communication System
SDATA
SDIR
SCK
EXT_IRQ1
3. Key Operaiton
For details of the key operation, refer to the instruction manual.
SCAN
SCAN
OUT
IN
0
1
MAIN SW-PLAY POSITION
2
3
0
CF_IN
DOWN
-
1
TEST
MAIN SW-LCD OFF
POSITION
RIGHT
SET
Table 4-2. Key Operation
2
MAIN SW-LCD ON
POSITION
LEFT
MODE
ASIC
3
SHUTTER 1stSHUTTER 2nd
COVER SW
UP
FOCUS SW
– 9 –
Page 4
4. Power Supply Control
The 8-bit microprocessor controls the power supply for the overall system.
The following is a description of how the power supply is turned on and off. When the battery is attached, a regulated 3.2 V
voltage is normally input to the 8-bit microprocessor (IC301) by IC302, so that clock counting and key scanning is carried out
even when the power switch is turned off, so that the camera can start up again. When the battery is removed, the 8-bit microprocessor operates in sleep mode using the backup capacitor. At this time, the 8-bit microprocessor only carries out clock
counting, and waits in standby for the battery to be attached again. When a switch is operated, the 8-bit microprocessor supplies
power to the system as required.
The 8-bit microprocessor first sets the P ON signal at pin (34) to high, and then turns on the DC/DC converter for the digital
system. After this, it sets RESET B signal at pin (33) to high so that the ASIC is set to the active condition.
After this, in case of driving the CCD, it sets the P (A) ON signal at pin (176) of the ASIC to high, and then turns on the DC/DC
converter for the analog system.
If the LCD monitor is on, the LCD ON signal at pin (175) of the ASIC set to high, and the DC/DC converter for the LCD monitor
is turned on. Once it is completed, the ASIC returns to the reset condition, all DC/DC converters are turned off and the power
supply to the whole system is halted.
ASIC,
memory
Power voltage
Power OFF
Power switch ON-
Auto power OFF
Shutter switch ON
CAMERA
Resolution, flash, self-timer switch ON
LCD finder
Play back
Table 4-3. Camera Mode
Note) 4 MHz = Main clock operation, 32 kHz = Sub clock operation
3.3 V
OFF
OFF
ON
OFF
ON
ON
CCD
5 V (A)
+12 V etc.
OFF
OFF
→→
ON
→OFF
→→
OFF
ON
OFF
8 bit
CPU
3.2 V
(ALWAYS)
32KHz OFF
4 MHz OFF
4 MHz OFF
4 MHz OFF
4 MHz ON
4 MHz ON
MONITOR
+12 V etc.
LCD
– 10 –
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